Sappers clearing the last mines from the beach front of a former French luxury hotel, now in use as a rest club for troops of 3rd Division, 15 July 1944.

The Long Tail Of War: Finding Unexploded Ordnance Before It Finds Us

September 19, 2022 by Maya Posch 38 Comments

Long after the enemy forces have laid down their arms, peace accords have been signed and victories celebrated, there is still a heavy toll to be paid. Most of this comes in the form of unexploded ordnance, including landmines and the severe pollution from heavy metals and other contaminants that can make large areas risky to lethal to enter. Perhaps the most extreme example of this lasting effect is the Zone Rouge (Red Zone) in France, which immediately after the First World War came to a close comprised 1,200 square kilometers.

Within this zone, contamination with heavy metals is so heavy that some areas do not support life, while unexploded shells – some containing lethal gases – and other unexploded ordnance is found throughout the soil. To this day much of the original area remains off-limits, though injuries from old, but still very potent ordnance are common around its borders. Clean-up of the Zone Rouge is expected to take hundreds of years. Sadly, this a pattern that is repeated throughout much of the world. While European nations stumble over ordnance from its two world wars, nations in Africa, Asia and elsewhere struggle with the legacy from much more recent conflicts.

Currently, in Europe’s most recent battlefield, more mines are being laid, booby traps set and unexploded shells and other ordnance scattered where people used to live. Clearing these areas, to make them safe for a return of their inhabitants has already begun in Ukraine, but just like elsewhere in the world, it is an arduous and highly dangerous process with all too often lethal outcomes.

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As Europe Goes To LEDs, Scientists Worry

September 19, 2022 by Al Williams 271 Comments

There was a time when street lighting means someone had to go light the lamps. Electricity changed that, but street and outdoor lighting has been quietly going through a new revolution: LEDs. The problem, though, is that LEDs provide what scientists call “broad white” light and there are concerns about the impact the unnatural lighting will have on ecosystems, including people and animals.

Of course, the first step in worrying about something is to measure it. You would think that satellites would have a bird’s-eye view of the nighttime lighting landscape, and, of course, they do. But most of the imagery isn’t suitable for looking at the spectrum of wavelength data scientists need to quantify what they call ALAN — Artificial Light at Night.

The ISS imaging is, however, sufficient. Using special data techniques, they were able to track the adoption of LEDs over sodium lights and other technologies between 2012-2013 and 2014-2020 across Europe. For example, in the title image, you can see Belgium with an orange tint indicating low-pressure sodium lights. The Netherlands, France, and the UK have a more yellow hue, indicating high-pressure sodium lamps. Germany is more of a blue color due to fluorescent and mercury vapor bulbs.

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Digital Light Pipes Clock various view of seven-segment display using illuminated light-pipes

LED Clock Has Its Pipes On Display

September 19, 2022 by Dave Walker 4 Comments

For most hackers and makers, building a clock is a rite of passage. Few, though, will be as unusual and engaging as this design by [TerraG2].

By combining addressable LEDs, light pipes and 7-segment displays, [TerraG2] has built a timepiece that looks great and will surely be a great conversation starter as well. It’s packed full of features such as automatic brightness control, an accelerometer controlled user interface, and WiFi to make sure it’s always accurate.

partial rear view of the clock showing illuminated light pipes — Partial rear view of the clock showing illuminated light pipes

The decision to leave the light pipes visible behind the main display really makes the project stand out from other clock builds, and the methods [TerraG2] has used to achieve this look will no doubt be transferable to a host of other projects.

The LEDs are courtesy of a standard 8×8 RGB matrix, with a custom 3D-printed shroud to hold the light pipes in place and a clever connector at the other end to illuminate the segments. With two LEDs per segment, seven segments per digit, and four digits, there’s even room for some extra features down the line if you can think of a use for those eight spare LEDs.

The brain of the project is an ESP8266 D1 with an MPU6050 inertial measurement unit (IMU) to detect when it’s flipped over to change the color scheme.

Full documentation is on Github, and a video of the clock in use is after the break.

Light pipes have been used to great effect in some other clock projects we’ve seen, such as this modern Nixie clock and this “clock of clocks”, as well as in this light organ that we showed recently.

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